1. Field of Invention
The present application relates to diamond cutting tools. More particularly, the present application concerns new and improved diamond mining core drill bits or hole saws for cutting rock and earth, and to methods of manufacturing diamond mining core drill bits.
2. Description of Related Art
Diamond core drilling equipment is used extensively to drill circular or annular holes in a variety of materials. Annular holes are formed in rock, earth, concrete, asphalt, and related materials for a variety of reasons. For example, holes are drilled in rock during mining or during exploration for purposes of determining soil compaction, determining soil percolation or to perform other geological research. Further, for example, holes are also commonly drilled in concrete and similar materials for the purpose of correcting the settlement of pavement or to provide openings to utility conduit cells located beneath the surface of cast concrete floors of office and factory buildings. Further, for example, holes are also commonly drilled in concrete or masonry to facilitate the mounting of objects such as posts or pipes.
Examples of prior art diamond core drill bits or hole saws of a general type that are commonly used in construction and/or concrete applications are shown in Jedick, U.S. Pat. No. 5,996,571, which is assigned to the assignee of the present application. As discussed in the Jedick '571 patent, the segments of such bits are commonly attached using laser welding techniques.
Generally speaking, diamond core drilling equipment comprises a motor-driven core drill assembly including a down-hole mining core drill bit or hole saw. The core drill assembly may embody various configurations, but such assembly generally comprises a base and a guide column extending up from the base or a drilling rig. A carriage may be provided between the column and the motor for guiding the motor along the column as the pipe extensions and mining core drill bit are advanced beneath the ground surface. Generally, the core bit is attached to the pipe extensions using a driver or reaming tool.
The prior art provides various types of core drill bits for use in mining. However, the majority of commercial mining bits used today have cutting heads formed of a diamond impregnated material. More particularly, the cutting head comprises a plurality of cutting segments or teeth mounted at the distal end of the cylindrical body of the bit. Each of the segments is attached to the cylindrical body of the bit using an infiltration process. This, however, is a time consuming operation, it is costly, and may at times result in inadequate adhesion of the segments with the body. Often, the infiltrated material “drips” onto unintended portions of the body and must be cleaned afterwards. A substantial investment of energy and time may be required to clean the tool of the stray brazing material.